Overfuelling

[Rory's Dad]

I've had to replace the tps on my car and cannot, cannot get the bloomin' thing to run properly.

The ecu is working properly - I went to dta, paid £20 and 'all doin' what it should do.  The wiring to my new tps is now correct - Ive checked both the continuity and the voltages and it's all fine.  I've set the new closed and fully open throttle positions with Kevin Brown's help and laptop (and they are close to the previous values) and still the bloomin' thing won't run properly.  It starts on the second turn or so, then coughs and splutters with lots of back smoke and then won't run cleanly or idle.    

Plugs are black, so cleaned them up again and gave each cylinder a small teaspoon of oil and spun it round before I refitted the plugs (worried about bore washing).

I've also taken the fuel pressure regulator to bits, given it a good clean and the pressure guage is giving the correct values.

20xe, dta, jenveys, colvern tps and used to run realy well.  So please chaps, what do I try next??    

Rory's increasingly bad tempered Dad

[TIG Brother]

have you disturbed any gaskets when replacing the TPS?

might have a vacuum leak some causing the engine to fail into open circuit mode and running rich,

[melt]

Can you run the DTA software in Real Time Mapping to see what cell the ECU thinks it is in, should be 1,1 or there abouts.  But is it further up the range for some odd reason?

Mel

[pete g]

plugs were black and you also added oil.

i would replace plugs first with new they probaby breaking down

[Rory's Dad]

might have a vacuum leak some causing the engine to fail into open circuit mode and running rich,

I don't understand this - please explain.

[Rory's Dad]

Can you run the DTA software in Real Time Mapping to see what cell the ECU thinks it is in, should be 1,1 or there abouts.  But is it further up the range for some odd reason?

Mel

I don't understand this either    

[Rory's Dad]

plugs were black and you also added oil.

i would replace plugs first with new they probaby breaking down

The plugs were newish and have had no more than a half hours sporadic use.  They were black and wet but cleaned up nicely.  I don't know much about bore washing but could imagine how all that petrol (which I could smell) could have washed any oil away.  Was I wrong to do that??

Rory's Dad

[sailing]

I not very into fuel injection, but what if you disconnect the TPS and see if it runs any better or worse. If the tps is/was causing the problem it might eliminate it???

On carbs the tps is a refinement, not essential. Or am I talking a load of rubbish? in the case with injection??

[melt]

Can you run the DTA software in Real Time Mapping to see what cell the ECU thinks it is in, should be 1,1 or there abouts.  But is it further up the range for some odd reason?

Mel

I don't understand this either    

On the DTA software one of the headings is for Real Time Mapping.  You said that you can start the engine so if you have the ECU connected to your computer and the DTA software was on the screen for Real Time Mapping it will show at what position the ECU thinks it is taking its mapping from.  

On tickover the map position should be around column 1 for throttle position and about 1000rpm.  If your map position shows, say column 6 for throttle positon this could be the reason behind the over fuelling.  Just another place to look in your quest for a reason behind the problem!!  

If the fuel map isn't in the expected position (col 1 and approx 1000rpm) this could show a problem with the throttle pot.    

HTH

Mel

[Rory's Dad]

I think it's all OK Mel...

Part of my problem is that I don't have a old laptop that can see the ECU - hence my grateful thanks to Kevin Brown who a) has a laptop that works and b) knows his way aeround the DTA software.  DTA themselves said the ecu and the mapping looked just fine.  I've been trying to work outwards from a position of certainty

But maybe that's a way forward...

Rory's Dad

[Rory's Dad]

I not very into fuel injection, but what if you disconnect the TPS and see if it runs any better or worse. If the tps is/was causing the problem it might eliminate it???

On carbs the tps is a refinement, not essential. Or am I talking a load of rubbish? in the case with injection??

To help me pin down the fault can I disconnect the tps, the air temperature sensor, the water temperature sensor and/or anything else (one by one) without damage??

   

Rory's Dad

[cleowuss]

Martin

Is it just a case of starting and stopping the engine that has fowled the plugs or have you been out on the road??

Richard

[Kevin Jones]

Just to add a bit more context from what I have seen of Martin's problem. The jenveys and TPS have been replaced but the map should be correct for them, the replacements were supposed to be a direct match for what was fitted originally.

Initially the TPS would not read correctly although the car was drivable but obviously running very rich. Martin changed the wiring of the TPS and that appeared to resolve the problem in that the DTA was now reading the position OK.

However the engine would not idle now, again appears to be running very rich. I tried to take out some idle fueling, approx 50% I thought it sounded slightly happier but still would not idle. Also tried increasing the idle adjust but made b****r all difference. Ran out of time to look into it more.

I know little about 20xe's setup so can't really help much further unless Martin just wants to re-maps it. My best guess would be an injector size change but sure there are plenty of other possibilities.

[Blatman]

What was fitted before?

Has anything else been moved?

Has the fuel pump been moved?

And my current favourite...

Has the fuel pressure regulator been fitted the right way round? 'Cos if it's been re-plumbed in backwards, it'll over fuel like a b*****d and no amount of mapping will make a blind bit of difference...

[Rory's Dad]

Just to add some more detail to this story - I had the inlet manifold, the throttle bodies and air filter stolen       and had quite a struggle to get the insurance to pay up - which they did in the end.  I don't really want to discuss this but let's just say it seems to have been stolen to order and I thought it would be a simple job to replace like for like...

All the 'hardware' came from SBD and it all came together just fine.  The ecu loom was just snipped off.  I got a new mini loom made up for the new injectors and for the air temperature sensor (which was fitted to the backplate) and a new colvern tps with a 3pin plug which just plugged into the socket that remained.

So to answer Blatman's questions...

No the fuel pumps have not been touched (have a lifter, swirl pot and high presure pump).

No the fuel pressure regulator was not disturbed by the theft but I checked it in case some crap had got into it from the severed fuel pipe - and it seemed a possible source of the problem.  No possibility of it being round the wrong way.

While typing this up I have just wondered if I've got the supply to #4 injector and the temperature sensor muddled up.  That would confuse the ecu wouldn't it??  I'm sure I checked it carefully when I put it all together - I'll check it again...

Anyway, many thanks to all for your advice - keep it coming!    

Rory's Dad